
a = [[0],[1],[2],[3],[4],[5],[6],[7],[8],[9],[0],[1],[2],[3],[4],[5],[6],[7],[8],[9],[0],[1],[2],[3],[4],[5],[6],[7],[8],[9],[0],[1],[2],[3],[4],[5],[6],[7],[8],[9],[0],[1],[2],[3],[4],[5],[6],[7],[8],[9],[0],[1],[2],[3],[4],[5],[6],[7],[8],[9]]
c = a[0]                                 # [list(int)]
c.append(1)                              # []

b = [['']]                               # [list(list(str))]
d = b[0]                                 # [list(str)]
d.append('')                             # []

